Cherry-picking swiftasync support to the new stable branch.

clang/include/clang/AST/Attr.h

@@ -209,6 +209,8 @@ class ParameterABIAttr : public InheritableParamAttr {
     switch (getKind()) {
     case attr::SwiftContext:
       return ParameterABI::SwiftContext;
+    case attr::SwiftAsyncContext:
+      return ParameterABI::SwiftAsyncContext;
     case attr::SwiftErrorResult:
       return ParameterABI::SwiftErrorResult;
     case attr::SwiftIndirectResult:

clang/include/clang/Basic/Attr.td

@@ -2418,6 +2418,11 @@ def SwiftContext : ParameterABIAttr {
   let Documentation = [SwiftContextDocs];
 }
 
+def SwiftAsyncContext : ParameterABIAttr {
+  let Spellings = [Clang<"swift_async_context">];
+  let Documentation = [SwiftAsyncContextDocs];
+}
+
 def SwiftErrorResult : ParameterABIAttr {
   let Spellings = [Clang<"swift_error_result">];
   let Documentation = [SwiftErrorResultDocs];

clang/include/clang/Basic/AttrDocs.td

@@ -4551,6 +4551,19 @@ A context parameter must have pointer or reference type.
   }];
 }
 
+def SwiftAsyncContextDocs : Documentation {
+  let Category = DocCatVariable;
+  let Content = [{
+The ``swift_async_context`` attribute marks a parameter as having the
+special asynchronous context-parameter ABI treatment.
+
+This treatment generally passes the context value in a special register
+which is normally callee-preserved.
+
+A context parameter must have pointer or reference type.
+  }];
+}
+
 def SwiftErrorResultDocs : Documentation {
   let Category = DocCatVariable;
   let Content = [{

clang/include/clang/Basic/Specifiers.h

@@ -344,7 +344,12 @@ namespace clang {
     /// This parameter (which must have pointer type) uses the special
     /// Swift context-pointer ABI treatment.  There can be at
     /// most one parameter on a given function that uses this treatment.
-    SwiftContext
+    SwiftContext,
+
+    /// This parameter (which must have pointer type) uses the special
+    /// Swift asynchronous context-pointer ABI treatment.  There can be at
+    /// most one parameter on a given function that uses this treatment.
+    SwiftAsyncContext,
   };
 
   /// Assigned inheritance model for a class in the MS C++ ABI. Must match order

clang/lib/AST/ItaniumMangle.cpp

@@ -2941,6 +2941,7 @@ CXXNameMangler::mangleExtParameterInfo(FunctionProtoType::ExtParameterInfo PI) {
 
   // All of these start with "swift", so they come before "ns_consumed".
   case ParameterABI::SwiftContext:
+  case ParameterABI::SwiftAsyncContext:
   case ParameterABI::SwiftErrorResult:
   case ParameterABI::SwiftIndirectResult:
     mangleVendorQualifier(getParameterABISpelling(PI.getABI()));

clang/lib/AST/TypePrinter.cpp

@@ -847,6 +847,8 @@ StringRef clang::getParameterABISpelling(ParameterABI ABI) {
     llvm_unreachable("asking for spelling of ordinary parameter ABI");
   case ParameterABI::SwiftContext:
     return "swift_context";
+  case ParameterABI::SwiftAsyncContext:
+    return "swift_async_context";
   case ParameterABI::SwiftErrorResult:
     return "swift_error_result";
   case ParameterABI::SwiftIndirectResult:

clang/lib/CodeGen/CGCall.cpp

@@ -2356,6 +2356,10 @@ void CodeGenModule::ConstructAttributeList(
     case ParameterABI::SwiftContext:
       Attrs.addAttribute(llvm::Attribute::SwiftSelf);
       break;
+
+    case ParameterABI::SwiftAsyncContext:
+      Attrs.addAttribute(llvm::Attribute::SwiftAsync);
+      break;
     }
 
     if (FI.getExtParameterInfo(ArgNo).isNoEscape())

clang/lib/Sema/SemaDeclAttr.cpp

@@ -4958,6 +4958,14 @@ void Sema::AddParameterABIAttr(Decl *D, const AttributeCommonInfo &CI,
     D->addAttr(::new (Context) SwiftContextAttr(Context, CI));
     return;
 
+  case ParameterABI::SwiftAsyncContext:
+    if (!isValidSwiftContextType(type)) {
+      Diag(CI.getLoc(), diag::err_swift_abi_parameter_wrong_type)
+          << getParameterABISpelling(abi) << /*pointer to pointer */ 0 << type;
+    }
+    D->addAttr(::new (Context) SwiftAsyncContextAttr(Context, CI));
+    return;
+
   case ParameterABI::SwiftErrorResult:
     if (!isValidSwiftErrorResultType(type)) {
       Diag(CI.getLoc(), diag::err_swift_abi_parameter_wrong_type)
@@ -8020,6 +8028,9 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
   case ParsedAttr::AT_SwiftContext:
     S.AddParameterABIAttr(D, AL, ParameterABI::SwiftContext);
     break;
+  case ParsedAttr::AT_SwiftAsyncContext:
+    S.AddParameterABIAttr(D, AL, ParameterABI::SwiftAsyncContext);
+    break;
   case ParsedAttr::AT_SwiftErrorResult:
     S.AddParameterABIAttr(D, AL, ParameterABI::SwiftErrorResult);
     break;

clang/lib/Sema/SemaType.cpp

@@ -2783,6 +2783,10 @@ static void checkExtParameterInfos(Sema &S, ArrayRef<QualType> paramTypes,
       checkForSwiftCC(paramIndex);
       continue;
 
+    case ParameterABI::SwiftAsyncContext:
+      // FIXME: might want to require swiftasynccc when it exists
+      continue;
+
     // swift_error parameters must be preceded by a swift_context parameter.
     case ParameterABI::SwiftErrorResult:
       checkForSwiftCC(paramIndex);

clang/test/CodeGen/arm-swiftcall.c

@@ -6,6 +6,7 @@
 #define OUT __attribute__((swift_indirect_result))
 #define ERROR __attribute__((swift_error_result))
 #define CONTEXT __attribute__((swift_context))
+#define ASYNC_CONTEXT __attribute__((swift_async_context))
 
 /*****************************************************************************/
 /****************************** PARAMETER ABIS *******************************/
@@ -53,6 +54,9 @@ void test_context_error_1() {
 SWIFTCALL void context_error_2(short s, CONTEXT int *self, ERROR float **error) {}
 // CHECK-LABEL: define{{.*}} void @context_error_2(i16{{.*}}, i32* swiftself{{.*}}, float** swifterror %0)
 
+SWIFTCALL void async_context_1(ASYNC_CONTEXT void *self) {}
+// CHECK-LABEL: define {{.*}} void @async_context_1(i8* swiftasync
+
 /*****************************************************************************/
 /********************************** LOWERING *********************************/
 /*****************************************************************************/

clang/test/Misc/pragma-attribute-supported-attributes-list.test

@@ -153,6 +153,7 @@
 // CHECK-NEXT: SetTypestate (SubjectMatchRule_function_is_member)
 // CHECK-NEXT: SpeculativeLoadHardening (SubjectMatchRule_function, SubjectMatchRule_objc_method)
 // CHECK-NEXT: SwiftAsync (SubjectMatchRule_function, SubjectMatchRule_objc_method)
+// CHECK-NEXT: SwiftAsyncContext (SubjectMatchRule_variable_is_parameter)
 // CHECK-NEXT: SwiftAsyncName (SubjectMatchRule_objc_method, SubjectMatchRule_function)
 // CHECK-NEXT: SwiftBridgedTypedef (SubjectMatchRule_type_alias)
 // CHECK-NEXT: SwiftContext (SubjectMatchRule_variable_is_parameter)

clang/test/Sema/attr-swiftcall.c

@@ -5,6 +5,7 @@
 #define INDIRECT_RESULT __attribute__((swift_indirect_result))
 #define ERROR_RESULT __attribute__((swift_error_result))
 #define CONTEXT __attribute__((swift_context))
+#define ASYNC_CONTEXT __attribute__((swift_async_context))
 
 int notAFunction SWIFTCALL; // expected-warning {{'swiftcall' only applies to function types; type here is 'int'}}
 void variadic(int x, ...) SWIFTCALL; // expected-error {{variadic function cannot use swiftcall calling convention}}
@@ -29,3 +30,8 @@ void context_nonswift(CONTEXT void *context); // expected-error {{'swift_context
 void context_bad_type(CONTEXT int context) SWIFTCALL; // expected-error {{'swift_context' parameter must have pointer type; type here is 'int'}}
 void context_okay(CONTEXT void *context) SWIFTCALL;
 void context_okay2(CONTEXT void *context, void *selfType, char **selfWitnessTable) SWIFTCALL;
+
+void async_context_okay_for_now(ASYNC_CONTEXT void *context);
+void async_context_bad_type(ASYNC_CONTEXT int context) SWIFTCALL; // expected-error {{'swift_async_context' parameter must have pointer type; type here is 'int'}}
+void async_context_okay(ASYNC_CONTEXT void *context) SWIFTCALL;
+void async_context_okay2(ASYNC_CONTEXT void *context, void *selfType, char **selfWitnessTable) SWIFTCALL;

llvm/docs/LangRef.rst

@@ -1254,6 +1254,12 @@ Currently, only the following parameter attributes are defined:
     a valid attribute for return values and can only be applied to one
     parameter.
 
+``swiftasync``
+    This indicates that the parameter is the asynchronous context parameter and
+    triggers the creation of a target-specific extended frame record to store
+    this pointer. This is not a valid attribute for return values and can only
+    be applied to one parameter.
+
 ``swifterror``
     This attribute is motivated to model and optimize Swift error handling. It
     can be applied to a parameter with pointer to pointer type or a
@@ -11826,6 +11832,29 @@ Note that calling this intrinsic does not prevent function inlining or
 other aggressive transformations, so the value returned may not be that
 of the obvious source-language caller.
 
+'``llvm.swift.async.context.addr``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+      declare i8** @llvm.swift.async.context.addr()
+
+Overview:
+"""""""""
+
+The '``llvm.swift.async.context.addr``' intrinsic returns a pointer to
+the part of the extended frame record containing the asynchronous
+context of a Swift execution.
+
+Semantics:
+""""""""""
+
+If the function has a ``swiftasync`` parameter, that argument will initially
+be stored at the returned address. If not, it will be initialized to null.
+
 '``llvm.localescape``' and '``llvm.localrecover``' Intrinsics
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 

llvm/include/llvm/Bitcode/LLVMBitCodes.h

@@ -656,6 +656,7 @@ enum AttributeKindCodes {
   ATTR_KIND_MUSTPROGRESS = 70,
   ATTR_KIND_NO_CALLBACK = 71,
   ATTR_KIND_HOT = 72,
+  ATTR_KIND_SWIFT_ASYNC = 73,
 };
 
 enum ComdatSelectionKindCodes {

llvm/include/llvm/CodeGen/TargetCallingConv.h

@@ -39,6 +39,7 @@ namespace ISD {
     unsigned IsPreallocated : 1; ///< ByVal without the copy
     unsigned IsSplitEnd : 1;   ///< Last part of a split
     unsigned IsSwiftSelf : 1;  ///< Swift self parameter
+    unsigned IsSwiftAsync : 1;  ///< Swift async context parameter
     unsigned IsSwiftError : 1; ///< Swift error parameter
     unsigned IsCFGuardTarget : 1; ///< Control Flow Guard target
     unsigned IsHva : 1;        ///< HVA field for
@@ -63,11 +64,12 @@ namespace ISD {
 
   public:
     ArgFlagsTy()
-      : IsZExt(0), IsSExt(0), IsInReg(0), IsSRet(0), IsByVal(0), IsByRef(0),
-          IsNest(0), IsReturned(0), IsSplit(0), IsInAlloca(0), IsPreallocated(0),
-          IsSplitEnd(0), IsSwiftSelf(0), IsSwiftError(0), IsCFGuardTarget(0),
-          IsHva(0), IsHvaStart(0), IsSecArgPass(0), ByValOrByRefAlign(0),
-          OrigAlign(0), IsInConsecutiveRegsLast(0), IsInConsecutiveRegs(0),
+        : IsZExt(0), IsSExt(0), IsInReg(0), IsSRet(0), IsByVal(0), IsByRef(0),
+          IsNest(0), IsReturned(0), IsSplit(0), IsInAlloca(0),
+          IsPreallocated(0), IsSplitEnd(0), IsSwiftSelf(0), IsSwiftAsync(0),
+          IsSwiftError(0), IsCFGuardTarget(0), IsHva(0), IsHvaStart(0),
+          IsSecArgPass(0), ByValOrByRefAlign(0), OrigAlign(0),
+          IsInConsecutiveRegsLast(0), IsInConsecutiveRegs(0),
           IsCopyElisionCandidate(0), IsPointer(0), ByValOrByRefSize(0),
           PointerAddrSpace(0) {
       static_assert(sizeof(*this) == 3 * sizeof(unsigned), "flags are too big");
@@ -100,6 +102,9 @@ namespace ISD {
     bool isSwiftSelf() const { return IsSwiftSelf; }
     void setSwiftSelf() { IsSwiftSelf = 1; }
 
+    bool isSwiftAsync() const { return IsSwiftAsync; }
+    void setSwiftAsync() { IsSwiftAsync = 1; }
+
     bool isSwiftError() const { return IsSwiftError; }
     void setSwiftError() { IsSwiftError = 1; }
 

llvm/include/llvm/CodeGen/TargetFrameLowering.h

@@ -157,6 +157,14 @@ class TargetFrameLowering {
   /// returns false, spill slots will be assigned using generic implementation.
   /// assignCalleeSavedSpillSlots() may add, delete or rearrange elements of
   /// CSI.
+  virtual bool assignCalleeSavedSpillSlots(MachineFunction &MF,
+                                           const TargetRegisterInfo *TRI,
+                                           std::vector<CalleeSavedInfo> &CSI,
+                                           unsigned &MinCSFrameIndex,
+                                           unsigned &MaxCSFrameIndex) const {
+    return assignCalleeSavedSpillSlots(MF, TRI, CSI);
+  }
+
   virtual bool
   assignCalleeSavedSpillSlots(MachineFunction &MF,
                               const TargetRegisterInfo *TRI,

llvm/include/llvm/CodeGen/TargetLowering.h

@@ -283,6 +283,7 @@ class TargetLoweringBase {
     bool IsPreallocated : 1;
     bool IsReturned : 1;
     bool IsSwiftSelf : 1;
+    bool IsSwiftAsync : 1;
     bool IsSwiftError : 1;
     bool IsCFGuardTarget : 1;
     MaybeAlign Alignment = None;
@@ -293,7 +294,7 @@ class TargetLoweringBase {
         : IsSExt(false), IsZExt(false), IsInReg(false), IsSRet(false),
           IsNest(false), IsByVal(false), IsByRef(false), IsInAlloca(false),
           IsPreallocated(false), IsReturned(false), IsSwiftSelf(false),
-          IsSwiftError(false), IsCFGuardTarget(false) {}
+          IsSwiftAsync(false), IsSwiftError(false), IsCFGuardTarget(false) {}
 
     void setAttributes(const CallBase *Call, unsigned ArgIdx);
   };

llvm/include/llvm/IR/Attributes.td

@@ -241,6 +241,9 @@ def SwiftError : EnumAttr<"swifterror">;
 /// Argument is swift self/context.
 def SwiftSelf : EnumAttr<"swiftself">;
 
+/// Argument is swift async context.
+def SwiftAsync : EnumAttr<"swiftasync">;
+
 /// Function must be in a unwind table.
 def UWTable : EnumAttr<"uwtable">;
 

llvm/include/llvm/IR/Intrinsics.td

@@ -472,7 +472,12 @@ def int_objc_arc_annotation_bottomup_bbstart  : Intrinsic<[],
 def int_objc_arc_annotation_bottomup_bbend  : Intrinsic<[],
                                                         [llvm_ptrptr_ty,
                                                          llvm_ptrptr_ty]>;
+//===--------------- Swift asynchronous context intrinsics ----------------===//
 
+// Returns the location of the Swift asynchronous context (usually stored just
+// before the frame pointer), and triggers the creation of a null context if it
+// would otherwise be unneeded.
+def int_swift_async_context_addr : Intrinsic<[llvm_ptrptr_ty], [], [IntrNoMem]>;
 
 //===--------------------- Code Generator Intrinsics ----------------------===//
 //

llvm/include/llvm/Target/TargetCallingConv.td

@@ -51,6 +51,11 @@ class CCIfPreallocated<CCAction A> : CCIf<"ArgFlags.isPreallocated()", A> {
 class CCIfSwiftSelf<CCAction A> : CCIf<"ArgFlags.isSwiftSelf()", A> {
 }
 
+/// CCIfSwiftAsync - If the current argument has swiftasync parameter attribute,
+/// apply Action A.
+class CCIfSwiftAsync<CCAction A> : CCIf<"ArgFlags.isSwiftAsync()", A> {
+}
+
 /// CCIfSwiftError - If the current argument has swifterror parameter attribute,
 /// apply Action A.
 class CCIfSwiftError<CCAction A> : CCIf<"ArgFlags.isSwiftError()", A> {

llvm/lib/AsmParser/LLLexer.cpp

@@ -695,6 +695,7 @@ lltok::Kind LLLexer::LexIdentifier() {
   KEYWORD(speculative_load_hardening);
   KEYWORD(swifterror);
   KEYWORD(swiftself);
+  KEYWORD(swiftasync);
   KEYWORD(uwtable);
   KEYWORD(willreturn);
   KEYWORD(writeonly);

llvm/lib/AsmParser/LLParser.cpp

@@ -1433,6 +1433,7 @@ bool LLParser::parseFnAttributeValuePairs(AttrBuilder &B,
     case lltok::kw_sret:
     case lltok::kw_swifterror:
     case lltok::kw_swiftself:
+    case lltok::kw_swiftasync:
     case lltok::kw_immarg:
     case lltok::kw_byref:
       HaveError |=
@@ -1759,6 +1760,7 @@ bool LLParser::parseOptionalParamAttrs(AttrBuilder &B) {
     case lltok::kw_signext:         B.addAttribute(Attribute::SExt); break;
     case lltok::kw_swifterror:      B.addAttribute(Attribute::SwiftError); break;
     case lltok::kw_swiftself:       B.addAttribute(Attribute::SwiftSelf); break;
+    case lltok::kw_swiftasync:      B.addAttribute(Attribute::SwiftAsync); break;
     case lltok::kw_writeonly:       B.addAttribute(Attribute::WriteOnly); break;
     case lltok::kw_zeroext:         B.addAttribute(Attribute::ZExt); break;
     case lltok::kw_immarg:          B.addAttribute(Attribute::ImmArg); break;
@@ -1864,6 +1866,7 @@ bool LLParser::parseOptionalReturnAttrs(AttrBuilder &B) {
     case lltok::kw_sret:
     case lltok::kw_swifterror:
     case lltok::kw_swiftself:
+    case lltok::kw_swiftasync:
     case lltok::kw_immarg:
     case lltok::kw_byref:
       HaveError |=

llvm/lib/AsmParser/LLToken.h

@@ -238,6 +238,7 @@ enum Kind {
   kw_strictfp,
   kw_swifterror,
   kw_swiftself,
+  kw_swiftasync,
   kw_uwtable,
   kw_willreturn,
   kw_writeonly,

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -1519,6 +1519,8 @@ static Attribute::AttrKind getAttrFromCode(uint64_t Code) {
     return Attribute::SwiftError;
   case bitc::ATTR_KIND_SWIFT_SELF:
     return Attribute::SwiftSelf;
+  case bitc::ATTR_KIND_SWIFT_ASYNC:
+    return Attribute::SwiftAsync;
   case bitc::ATTR_KIND_UW_TABLE:
     return Attribute::UWTable;
   case bitc::ATTR_KIND_WILLRETURN:

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -732,6 +732,8 @@ static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
     return bitc::ATTR_KIND_SWIFT_ERROR;
   case Attribute::SwiftSelf:
     return bitc::ATTR_KIND_SWIFT_SELF;
+  case Attribute::SwiftAsync:
+    return bitc::ATTR_KIND_SWIFT_ASYNC;
   case Attribute::UWTable:
     return bitc::ATTR_KIND_UW_TABLE;
   case Attribute::WillReturn:

llvm/lib/CodeGen/GlobalISel/CallLowering.cpp

@@ -54,6 +54,8 @@ addFlagsUsingAttrFn(ISD::ArgFlagsTy &Flags,
     Flags.setReturned();
   if (AttrFn(Attribute::SwiftSelf))
     Flags.setSwiftSelf();
+  if (AttrFn(Attribute::SwiftAsync))
+    Flags.setSwiftAsync();
   if (AttrFn(Attribute::SwiftError))
     Flags.setSwiftError();
 }